1. Technical Field
The present disclosure relates to a wireless power transmission system provided with a function of detecting a foreign object between coils, and a power transmission device of the wireless power transmission system.
2. Description of the Related Art
In recent years, electronic devices and EV devices that involve mobility such as that afforded by a portable telephone or an electric automobile have become widespread. The development of wireless power transmission systems targeting such devices has been advancing. Methods such as the electromagnetic induction method, the magnetic field resonance method (resonance magnetic field coupling method), and the electric field coupling method are known as examples of wireless power transmission technologies.
A wireless power transmission system according to the electromagnetic induction method and the magnetic field resonance method is provided with a power transmission device equipped with a power transmission coil and a power reception device equipped with a power reception coil. Power can be transmitted without electrodes being brought into direct contact, as a result of the power reception coil supplementing the magnetic field produced by the power transmission coil. A wireless power transmission system such as this is disclosed in Japanese Unexamined Patent Application Publication No. 2009-11129 and Japanese Unexamined Patent Application Publication No. 2012-016171, for example.